1. Technical Field
The present invention relates to a control device, a display device, and a method of controlling a display device.
2. Related Art
An electrophoretic display device is configured by sealing an electrophoretic dispersion liquid that contains one or more types of electrophoretic particles and an electrophoretic dispersion medium between opposing electrode plates, at least one of which is transparent, forming one set. By applying a voltage between two electrodes, the electrophoretic particles move inside the electrophoretic dispersion medium so as to change the distribution thereof. Accordingly, the optical reflection characteristics thereof change, thereby information can be displayed. At this time, in a case where one of the electrodes is configured by a plurality of pixel electrodes separated from one another, by controlling the electric potential of each pixel electrode, the distribution of the particles can be formed so as to be different for each pixel, whereby an image can be formed.
Since it takes a relatively long time to change the display state of an electrophoretic display device, in order to rewrite the display of an active-matrix-type electrophoretic display device, a technology of performing a rewriting operation by using a plurality of frames is known. Here, when a writing operation is started once for the entire screen, as in a liquid crystal display device, for rewriting the display of an electrophoretic display device, a new writing operation cannot be started for several frames. Accordingly, the sensed response speed is low. As a method of solving such a problem, as disclosed in JP-A-2009-251615 or the like, a method is known in which a writing operation is performed by performing a pipeline process in units of a partial area. According to this method, in a case where an image is continuously written into two partial areas of the screen, which do not overlap each other, even when a writing operation for one partial area, which was started first, has not been completed, a writing operation for the other partial area, which is started later, can be started. Therefore, the display speed is improved.
However, according to the method disclosed in JP-A-2009-251615, in a case where partial areas overlap each other in part, the driving of a partial area for which a writing operation is started later needs to wait until a writing operation for another partial area, which was started first, is completed. Accordingly, the display speed is lowered. Although a method may be used in which the partial areas are controlled by software so as not to overlap each other, in such a case, the development of the software is highly complicated.